[Patrick Stickler, Nokia/Finland, (+358 40) 801 9690, patrick.stickler@nokia.com]
----- Original Message -----
From: "ext pat hayes" <phayes@ai.uwf.edu>
To: "Jeremy Carroll" <jjc@hpl.hp.com>
Cc: <w3c-rdfcore-wg@w3.org>
Sent: 30 October, 2002 19:50
Subject: RE: rdfs:StringLiteral
>
> >thanks Patrick I misspoke.
> >
> >Should all datatypes be subclass of rdfs:Literal; or maybe only the datatype
> >xsd:string should be a subclass of rdfs:Literal
>
> My understanding is that rdfs:Literal is the class of all possible
> literal values.
"literal values" sounds like an oxymoron to me. We have either
lexical forms or values, and if the L2V mapping happens to map
a lexical form to a value that is string equal to the lexical
form,, fine, but one can still argue that both exist insofar
as the semantics are concerned.
Do you mean "lexical forms"? If so, then while we can say that
rdfs:Literal is the class of all possible lexical forms, I don't
see how that fits into RDFS Class semantics, since that is a
syntactic based membership and not a semantic one.
I personally consider rdfs:Literal to be a bug. Its membership is
defined by M&S as a set of structural components of the graph, not
the denotation of members of a class. I.e. it's a syntactic class
according to the abstract syntax, not a semantic class according
to the denotation of the literals.
We can perhaps salvage the term by using it to reflect the semantics
proposed by Jeremy for rdfs:StringLiteral, but I don't see how it
is possible (or rather reasonable) to have any relation whatsoever
between arbitrary datatype classes and rdfs:Literal.
Patrick